1. Field of the Invention
This invention relates to shock absorbers for use on vehicle bumper bars, on highway guard rail posts and for other purposes where absorption of impact forces, shocks or vibration is required.
2. Description of the Prior Art
Shock absorbers are known consisting of telescopic members such as pistons and cylinders with resilient means or displaceable or compressible fluids to retard relative movement between the members and thus damp or absorb shock on one of the members while the other member is supported by a fixed structure.
Such known shock absorbers often damp or absorb the shocks proportionately to the relative movement between the members. Where a varying resistance to a shock is required additional means such as springs or additional pistons and cylinders are employed but such constructions are complicated and expensive to manufacture as well as increasing the liability to failure due to the number of parts.
The main object of the present invention is to provide a simple form of shock absorber which can be assembled with predetermined characteristics to accommodate resistance in a predetermined sequence to a wide range of shocks.